Vapour decline 'may explain global warming slowdown'

29/01/2010 - 09:37:32
A new report suggests a slowdown in global warming in recent years may have been caused by a decline in water vapour in the stratosphere.

While climate warming is continuing, the increase in temperatures is not as rapid as in the 1990s, according to research.

But balloon and satellite observations show the amount of water vapour in a layer about 10 miles high declined after 2000.

The reason for the decline is unknown, according to researchers led by Susan Solomon of the US National Oceanic and Atmospheric Administration.

But the researchers said the decline of water vapour in the stratosphere would reduce the rate of global warming expected from gases such as carbon dioxide.

They report their findings in the online edition of the journal Science.